CRABP2 regulates infiltration of cancer-associated fibroblasts and immune response in melanoma

Finding biomarkers for immunotherapy is an urgent issue in cancer treatment.Cellular retinoic acid-binding protein 2(CRABP2)is a controversial factor in the occurrence and development of human tumors.However,there is limited research on the relationship between CRABP2 and immunotherapy response.This study found that negative correlations of CRABP2 and immune checkpoint markers(PD-1,PD-L1,and CTLA-4)were observed in breast invasive carcinoma(BRCA),skin cutaneous melanoma(SKCM),stomach adenocarcinoma(STAD)and testicular germ cell tumors(TGCT).In particular,in SKCM patients who were treated with PD-1 inhibitors,high levels of CRABP2 predicted poor prognosis.Additionally,CRABP2 expression was elevated in cancer-associated fibroblasts(CAFs)at the single-cell level.The expression of CRABP2 was positively correlated with markers of CAFs,such as MFAP5,PDPN,ITGA11,PDGFRα/βand THY1 in SKCM.To validate the tumor-promoting effect of CRABP2 in vivo,SKCM xenograft mice models with CRABP2 overexpression have been constructed.These models showed an increase in tumor weight and volume.Enrichment analysis indicated that CRABP2 may be involved in immunerelated pathways of SKCM,such as extracellular matrix(ECM)receptor interaction and epithelial-mesenchymal transition(EMT).The study suggests that CRABP2 may regulate immunotherapy in SKCM patients by influencing infiltration of CAFs.In conclusion,this study provides new insights into the role of CRABP2 in immunotherapy response.The findings suggest that CRABP2 may be a promising biomarker for PD-1 inhibitors in SKCM patients.Further research is needed to confirm these findings and to explore the clinical implications of CRABP2 in immunotherapy.

Impact of STAT-signaling pathway on cancer-associated fibroblasts in colorectal cancer and its role in immunosuppression

Colorectal cancer(CRC)remains one of the most commonly diagnosed and deadliest types of cancer worldwide.CRC displays a desmoplastic reaction(DR)that has been inversely associated with poor prognosis;less DR is associated with a better prognosis.This reaction generates excessive connective tissue,in which cancer-associated fibroblasts(CAFs)are critical cells that form a part of the tumor microenvironment.CAFs are directly involved in tumorigenesis through different mechanisms.However,their role in immunosuppression in CRC is not well understood,and the precise role of signal transducers and activators of transcription(STATs)in mediating CAF activity in CRC remains unclear.Among the myriad chemical and biological factors that affect CAFs,different cytokines mediate their function by activating STAT signaling pathways.Thus,the harmful effects of CAFs in favoring tumor growth and invasion may be modulated using STAT inhibitors.Here,we analyze the impact of different STATs on CAF activity and their immunoregulatory role.

Astragaloside Ⅳ inhibits pathological functions of gastric cancer-associated fibroblasts

AIM To investigate the inhibitory effect of astragaloside IV on the pathological functions of cancer-associated fibroblasts,and to explore the underlying mechanism.METHODS Paired gastric normal fibroblast(GNF) and gastric cancer-associated fibroblast(GCAF) cultures were established from resected tissues. GCAFs were treated with vehicle control or different concentrations of astragaloside Ⅳ. Conditioned media were prepared from GNFs,GCAFs,control-treated GCAFs,and astragaloside Ⅳ-treated GCAFs,and used to culture BGC-823 human gastric cancer cells. Proliferation,migration and invasion capacities of BGC-823 cells were determined by MTT,wound healing,and Transwell invasion assays,respectively. The action mechanism of astragaloside Ⅳ was investigated by detecting the expression of micro RNAs and the expression and secretion of the oncogenic factor,macrophage colonystimulating factor(M-CSF),and the tumor suppressive factor,tissue inhibitor of metalloproteinase 2(TIMP2),in different groups of GCAFs. The expression of the oncogenic pluripotency factors SOX2 and NANOG in BGC-823 cells cultured with different conditioned media was also examined.RESULTS GCAFs displayed higher capacities to induce BGC-823 cell proliferation,migration,and invasion than GNFs(P < 0.01). Astragaloside Ⅳ treatment strongly inhibited the proliferation-,migration-and invasion-promoting capacities of GCAFs(P < 0.05 for 10 μmol/L,P < 0.01 for 20 μmol/L and 40 μmol/L). Compared with GNFs,GCAFs expressed a lower level of micro RNA-214(P < 0.01) and a higher level of micro RNA-301 a(P < 0.01). Astragaloside Ⅳ treatment significantly upregulated micro RNA-214 expression(P < 0.01) and down-regulated micro RNA-301 a expression(P < 0.01) in GCAFs. Reestablishing the micro RNA expression balance subsequently suppressed M-CSF production(P < 0.01) and secretion(P < 0.05),and elevated TIMP2 production(P < 0.01) and secretion(P < 0.05). Consequently,the ability of GCAFs to increase SOX2 and NANOG expression in BGC-823 cells was abolished by astragaloside Ⅳ.CONCLUSION Astragaloside Ⅳ can inhibit the pathological functions of GCAFs by correcting their dysregulation of micro RNA expression,and it is promisingly a potent therapeutic agent regulating tumor microenvironment.

Role of cancer-associated fibroblasts in invasion and metastasis of gastric cancer

Cancer-associated fibroblasts(CAFs) are important components of various types of tumors,including gastric cancer(GC).During tumorigenesis and progression,CAFs play critical roles in tumor invasion and metastasis via a series of functions including extracellular matrix deposition,angiogenesis,metabolism reprogramming and chemoresistance.However,the mechanism of the interaction between gastric cancer cells and CAFs remains largely unknown.Micro RNAs(mi RNAs) are a class of non-coding small RNA molecules,and their expression in CAFs not only regulates the expression of a number of target genes but also plays an essential role in the communication between tumor cells and CAFs.In this review,we provide an overview of recent studies on CAF mi RNAs in GC and the relevant signaling pathways in gastrointestinal tumors.Focusing the attention on these signaling pathways may help us better understand their role in tumor invasion and metastasis and identify new molecular targets for therapeutic strategies.

Key players in pancreatic cancer-stroma interaction: cancer-associated fibroblasts, endothelial and inflammatory cells

Pancreatic cancer(PC) is the most aggressive type of common cancers, and in 2014, nearly 40000 patients died from the disease in the United States. Pancreatic ductal adenocarcinoma, which accounts for the majority of PC cases, is characterized by an intense stromal desmoplastic reaction surrounding the cancer cells. Cancer-associated fibroblasts(CAFs) are the main effector cells in the desmoplastic reaction, and pancreatic stellate cells are the most important source of CAFs. However, other important components of the PC stroma are inflammatory cells and endothelial cells. The aim of this review is to describe the complex interplay between PC cells and the cellular and noncellular components of the tumour stroma. Published data have indicated that the desmoplastic stroma protects PC cells against chemotherapy and radiation therapy and that it might promote the proliferation and migration of PC cells. However, in animal studies, experimental depletion of the desmoplastic stroma and CAFs has led to more aggressive cancers. Hence, the precise role of the tumour stroma in PC remains to be elucidated. However, it is likely that a contextdependent therapeutic modification, rather than pure depletion, of the PC stroma holds potential for the development of new treatment strategies for PC patients.

Cancer-associated fibroblasts in digestive tumors

The significant influence of tumor stroma on malignant cells has been extensively investigated in this era of targeted therapy. The tumor microenvironment, as a dynamic system, is orchestrated by various cells including tumor vascular composing cells, inflammatory cells and fibroblasts. As a major and important component in tumor stroma, increasing evidence has shown that spindle-shaped cancer-associated fibroblasts (CAFs) are a significant modifier of cancer evolution, and promote tumorigenesis, tumor invasion and metastasis by stimulating angiogenesis, malignant cell survival, epithelial-mesenchymal transition (EMT) and proliferation via direct cell-to-cell contact or secretion of soluble factors in most digestive solid tumors. CAFs are thought to be activated, characterized by the expression of &#x003b1;-smooth muscle actin, fibroblast activated protein, fibroblast specific protein, vimentin, fibronectin, etc. They are hypothesized to originate from normal or aged fibroblasts, bone marrow-derived mesenchymal cells, or vascular endothelial cells. EMT may also be an important process generating CAFs, and most probably, CAFs may originate from multiple cells. A close link exists between EMT, tumor stem cells, and chemo-resistance of tumor cells, which is largely orchestrated by CAFs. CAFs significantly induce immunosuppression, and may be a prognostic marker in various malignancies. Targeted therapy toward CAFs has displayed promising anticancer efficacy, which further reinforces the necessity to explore the relationship between CAFs and their hosts.

Two novel gastric cancer-associated genes identified by differential display

AIM To clone novel gastric cancer-associated genes and investigate their roles in gastric cancer occurrence.METHODS A method called differential display was used which allows the identification of differentially expressed genes by using PAGE to display PCR-amplified cDNA fragments between gastric cancer cells and normal gastric mucosa cells. These fragments were cloned into plasmid vector pUC18. Homology analysis was made after sequencing these fragments.RESULTS Two novel genes were identified compared with sequences from GenBank. One was registered with the AD number AF 051783. In situ hybridization showed that these two novel genes expressed specifically in gastric cancer tissues.CONCLUSION The two novel genes obtained by differential display were confirmed to be gastric cancer-associated genes using in situ hybridization.

Progress in the study of cancer-associated retinopathy in breast cancer patients

Cancer-associated retinopathy (CAR) typically has a sudden or progressive onset of severe visual loss and an ominous association with an occult malignancy which contains breast cancer. Pathologically, CAR is the degeneration of photoreceptors. But the precise mechanism has not been fully established, CAR may result from autoimmune mediated apoptosis. And in recent years, there also have been some results demonstrating that tumor derived angiogenic factors such as VEGF may also confer the development of CAR, which may offer novel avenues for the therapeutic intervention in CAR. Early initiation of immunosuppressive therapy is critical for vision preservation. Future developments in rapid identification and longitudinal quantification of antibody levels would enable individualized management in these patients. The goal of this review was to analyze the epidemiology, the clinical features, the diagnosis and management of retinopathy in the context of recent advances in the elucidation of breast cancer-associated retinopathy (BCAR) pathogenesis.

DETECTION OF CANCER-ASSOCIATED ANTIGEN IN FECES USING MONOCLONAL ANTIBODIES IN THE DIAGNOSIS OF COLON CARCINOMA

Monoclonal antibodies against colon and pancreatic cancer, CL-2, CL-3, PS-9, PS-10, were used to detect the associated antigens in feces of patients with gastrointestinal carcinoma and non-cancer diseases. Binding inhibition test by SABC-ELISA method were performed for the measurement of the antigen level. Results showed that the associated antigen detected in feces of patients with colon cancer were significantly higher than that of non-cancer disease or normal subjects. The positive rates were 61.1% as detected with CL-2; 53.4% with CL-3; 55.0%, PS-9; and 53.3% PS-10 in cancer patients while that in normal subjects were 7%; 9%; 8%; and 8% respectively. When 'cocktail' of CL-2, PS-9 and PS-10 were used, the positive rates were 92.5% in colon cancer and 14% in normal subjects. In seven out of the sixty patients with colon cancer studied who were graded as Dukes A, the results were all positive. The results seem superior to the serologic detection and may provide a promising new approach in the early diagnosis of colon cancer.

Research progress on the role of cancer-associated fibroblasts in tumorigenesis and development

Tumor microenvironment plays a very important role in the growth,invasion and metastasis of tumor cells.The tumor interstitial microenvironment is an important part of the tumor microenvironment,which includes two parts:the non-cellular and cellular components of the tumor interstitium,specifically including the extracellular matrix,blood vessels,and interstitial cells.Among them,activated interstitial fibroblasts,namely cancer-associated fibroblasts(CAFs),are the main components of tumor interstitial cells,which are most closely related to tumor interstitial fibrosis and tumor progress,and are expected to become a new target for cancer treatment.

Tumorigenic Responses of Cancer-Associated Stromal Fibroblasts after Ablative Radiotherapy: A Transcriptome-Profiling Study

Cancer-associated fibroblasts (CAFs) are key elements in the progression of cancer and thereby represent important targets for cancer therapies. Increased attention has been given to ablative radiotherapy in the clinics. Therefore, in this study we have aimed at identifying the transcriptional responses occurring in primary CAFs exposed to high-dose irradiation. Established primary CAFs obtained from non-small-cell lung cancer (NSCLC) patient material were irradiated with a single dose of 18 Gy and total RNA was isolated 24 hrs after treatment. Radiation-induced transcriptional alterations were investigated by gene expression analysis using genome-wide microarrays. Obtained results were verified by qRT-PCR of relevant genes. Confirmation of gene expression outcomes was achieved by diverse functional and expression assays including DNA damage response, measurements of reactive oxygen species (ROS) by flow cytometry and senescence-associated β-galactosidase. Irradiation resulted in differential expression of 680 genes of which 557 were up- and 127 down-regulated. Of those, 153 genes were differentially expressed with a fold-change greater than 1.0 and an adjusted p-value less than 0.05 across different comparisons (non-irradiated vs. irradiated). Expression patterns revealed profound changes in biological functions and processes involved in DNA repair, apoptosis, p53 pathway, autophagy, senescence, ROS production and immune response. CAFs display pro- and anti-tumorigenic effects after having received a single high-dose radiation. The measured effects will have an impact on the tumor microenvironment in respect to tumor growth and metastasis.

Dendritic nanomedicine enhances chemoimmunotherapy by disturbing metabolism of cancer-associated fibroblasts for deep penetration and activating function of immune cells

Inefficient drug penetration hurdled by the stroma in the tumor tissue leads to a diminished therapeutic effect for drugs and a reduced infiltration level of immune cells.Herein,we constructed a PEGylated dendritic epirubicin(Epi)prodrug(Epi-P4D)to regulate the metabolism of cancer-associated fibroblasts(CAFs),thus enhancing Epi penetration into both multicellular tumor spheroids(MTSs)and tumor tissues in mouse colon cancer(CT26),mouse breast cancer(4T1)and human breast cancer(MDA-MB-231)models.Enhanced cytotoxicity against CT26 MTSs and remarkable antitumor efficacy of Epi-P4D were ascribed to reduced fibronectin,α-SMA,and collagen secretion.Besides,thinning of the tumor tissue stroma and efficient eradication of tumor cells promoted the immunogenic cell death effect for dendritic cell(DC)maturation and subsequent immune activation,including elevating the CD4^(+)T cell population,reducing CD4^(+)and CD8^(+)T cell hyperactivation and exhaustion,and amplifying the natural killer(NK)cell proportion and effectively activating them.As a result,this dendritic nanomedicine thinned the stroma of tumor tissues to enhance drug penetration and facilitate immune cell infiltration for elevated antitumor efficacy.

Recent advances in cancer-associated fibroblast:Biomarkers,signaling pathways,and therapeutic opportunities

Anti-cancer therapies usually focus on tumor cells,but non-tumor stromal components in the tumor microenvironment also play vital roles in tumor initiation and progression,which may be the prognostic factors and potential therapeutic targets.Cancer-associated fibroblasts(CAFs)are the essential component in the tumor environment,exhibiting high heterogeneity in their cell origin and phenotype with diverse functions that influence tumor angiogenesis,immune systems,and metabolism.Single-cell RNA sequencing and genetically engineered mouse models have increased our understanding of CAF diversity,and many subtypes have been defined.However,the precise functions of these subtypes need to be studied and validated.Studies of signaling pathways and epigenetic changes in CAFs facilitate understanding of the phenotypes of CAFs and the crosstalk between tumor cells and CAFs to provide potential therapeutic targets.Some clinical trials,including phase III trials targeting CAFs,have been performed recently.However,few of these trials have generated promising results,which indicates that the complexity of CAFs in the tumor microenvironment remains largely unknown,and in-depth investigations of CAFs should be performed.This review summarizes the research on CAFs,focusing on the heterogeneity of their phenotypes and functions,specific signaling pathways,and the therapeutic strategies involving CAFs.Additionally,we briefly discuss the current technologies commonly used in CAF studies and describe the challenges and future perspectives of CAF research.

Signaling pathways in cancer-associated fibroblasts:recent advances and future perspectives

As a critical component of the tumor microenvironment(TME),cancerassociated fibroblasts(CAFs)play important roles in cancer initiation and progression.Well-known signaling pathways,including the transforming growth factor-β(TGF-β),Hedgehog(Hh),Notch,Wnt,Hippo,nuclear factor kappa-B(NF-κB),Janus kinase(JAK)/signal transducer and activator of transcription(STAT),mitogen-activated protein kinase(MAPK),and phosphoinositide 3-kinase(PI3K)/AKT pathways,as well as transcription factors,including hypoxia-inducible factor(HIF),heat shock transcription factor 1(HSF1),P53,Snail,and Twist,constitute complex regulatory networks in theTMEtomodulate the formation,activation,heterogeneity,metabolic characteristics and malignant phenotype of CAFs.Activated CAFs remodel the TME and influence the malignant biological processes of cancer cells by altering the transcriptional and secretory characteristics,and this modulation partially depends on the regulation of signaling cascades.The results of preclinical and clinical trials indicated that therapies targeting signaling pathways in CAFs demonstrated promising efficacy but were also accompanied by some failures(e.g.,NCT01130142 and NCT01064622).Hence,a comprehensive understanding of the signaling cascades in CAFs might help us better understand the roles of CAFs and the TME in cancer progression and may facilitate the development of more efficient and safer stroma-targeted cancer therapies.Here,we review recent advances in studies of signaling pathways in CAFs and briefly discuss some future perspectives on CAF research.

Targeting cancer-associated fibroblasts with hydroxyethyl starch nanomedicine boosts cancer therapy

Cancer-associated fibroblasts(CAFs)play an important role in facilitating the progression of triple-negative breast cancer(TNBC)by deteriorating the tumor mechanical microenvironment(TMME).Herein,we designed a CAFs-targeting nanomedicine by conjugating doxorubicin(DOX)-loaded hydroxyethyl starch-IR780 nanoparticles(NPs)with Cys-Arg-Glu-Lys-Ala(CREKA)peptide,which had a special affinity for fibronectin overexpressed on CAFs.After systemic administration,the NPs efficiently targeted CAFs and generated hyperthermia upon light irradiation,decreasing CAFs through the combination of chemo-and photothermal-therapies.Thus,a series of changes in TMME were achieved by reducing CAFs,which further disrupted the niche of cancer stem cells(CSCs)to affect their survival.As a result,the tumor growth was significantly inhibited in 4T1 tumors.The strategy of TMME modulation and CSCs elimination through targeting and depleting CAFs provides a novel therapeutic treatment for desmoplastic solid tumors.

Bifidobacterium adolescentis orchestrates CD143^(+)cancer-associated fibroblasts to suppress colorectal tumorigenesis by Wnt signaling-regulated GAS1

Background The interplay between gut microbiota and tumor microenvironment(TME)in the pathogenesis of colorectal cancer(CRC)is not well explored.Here,we elucidated the functional role of Bifidobacterium adolescentis(B.a)on CRC and investigated its possible mechanism on the manipulation of cancer-associated fibroblasts(CAFs)in CRC.Methods Different CRC animal models and various cell line models were established to explore the function of B.a on CRC.The single-cell RNA sequencing(scRNA-seq)or flow cytometry was used to detect the cell subsets in the TME of CRC.Western blot,quantitative real-time polymerase chain reaction(qRT-PCR),or immunofluorescence staining were performed to examine the activation of Wnt signaling and growth arrest specific 1(GAS1)on CD143+CAFs.Chromatin immunoprecipitation quantitative real-time PCR(CHIP-qPCR)was performed to investigate the regulation of transcription factor 4(TCF4)on GAS1.Multi-immunofluorescence assay examined the expression level of CD143 and GAS1 on tissue microarray.Results We found that B.a abundance was significantly reduced in CRC patients from two independent cohorts and the bacteria database of GMrepo.Supplementation with B.a suppressed ApcMin/+spontaneous or AOM/DSS-induced tumorigenesis in mice.scRNA-seq revealed that B.a facilitated a subset of CD143+CAFs by inhibiting the infiltration of Th2 cells,while promoting the TNF-alpha+B cells in TME.CD143+CAFs highly expressed GAS1 and exhibited tumor suppressive effect.Mechanistically,GAS1 was activated by the Wnt/β-catenin signaling in CD143+CAFs.B.a abundance was correlated with the expression level of CD143 and GAS1.The level of CD143+CAFs predicted the better survival outcome in CRC patients.Conclusions These results highlighted that B.a induced a new subset of CD143+CAFs by Wnt signaling-regulated GAS1 to suppress tumorigenesis and provided a novel therapeutic target for probiotic-based modulation of TME in CRC.

Single-cell transcriptome analysis reveals a cancer-associated fibroblast marker gene signature in hepatocellular carcinoma that predicts prognosis

Background and aims:Hepatocellular carcinoma(HCC)is one of the leading causes of cancer death.Multi-pathway combination therapy is used to treat HCC,and immunotherapy is also a routine part of treatment.As a major component of the tumor microenvironment(TME),cancer-associated fibroblasts(CAFs)actively participate in cancer progression through complex functions.However,because CAFs dynamically change during cancer development,most of the current treatment strategies targeting CAFs fail.We created a prognostic CAF marker gene signature(CAFMGS)to investigate the utility of CAFs as a prognostic factor and therapeutic target.Methods:Gene Expression Omnibus(GEO)single-cell RNA sequencing(Sc-RNA-seq)data were analyzed to identify CAF marker genes in HCC.The Cancer Genome Atlas(TCGA)database was used as a training cohort to construct the CAFMGS model and the International Cancer Genome Consortium(ICGC)dataset was used to validate the CAFMGS.Results:Marker genes in the CAFMGS model were(0.0001-SPP1),(0.0084-VCX3A),(0.0015-HMGA1),(0.0082-PLOD2),and(0.0075-CACYBP).The CAFMGS_score was separated into high-risk and low-risk groups based on the median of the patients’OS.Univariate and multivariate analyses confirmed that CAFMGS_score was an independent prognostic factor in the training group.CAFMGS_score was a more accurate prognostic indicator compared with clinicopathological score and tumor mutational burden score.Conclusion:CAFMGS offers a fresh perspective on stromal cell marker genes in HCC prognosis and expands our knowledge of CAF heterogeneity and functional diversity,perhaps paving the way for CAF-targeted immunotherapy in HCC patients.

Cancer-associated fibroblasts in breast cancer:Challenges and opportunities

The tumor microenvironment is proposed to contribute substantially to the progression of cancers,including breast cancer.Cancer-associated fibroblasts(CAFs)are the most abundant components of the tumor microenvironment.Studies have revealed that CAFs in breast cancer originate from several types of cells and promote breast cancer malignancy by secreting factors,generating exosomes,releasing nutrients,reshaping the extracellular matrix,and suppressing the function of immune cells.CAFs are also becoming therapeutic targets for breast cancer due to their specific distribution in tumors and their unique biomarkers.Agents interrupting the effect of CAFs on surrounding cells have been developed and applied in clinical trials.Here,we reviewed studies examining the heterogeneity of CAFs in breast cancer and expression patterns of CAF markers in different subtypes of breast cancer.We hope that summarizing CAFrelated studies from a historical perspective will help to accelerate the development of CAF-targeted therapeutic strategies for breast cancer.

Breast cancer-associated fibroblasts： their roles in tumor nitiation, progression and clinical applications

Breast cancer is the most common malignant tumor in women, and the incidence of this disease has increased in recent years because of changes in diet, living environment, gestational age, and other unknown factors. Previous studies focused on cancer cells, but an increasing number of recent studies have analyzed the contribution of cancer microenvironment to the initiation and progression of breast cancer. Cancer-associated libroblasts （CAFs）, the most abundant cells in tumor stroma, secrete various active biomolecules, including extraceHular matrix components, growth factors, cytokines, proteases, and hormones. CAFs not only facilitate the initiation, growth, angiogenesis, invasion, and metastasis of cancer but also serve as biomarkers in the clinical diagnosis, therapy, and prognosis of breast cancer. In this article, we reviewed the literature and summarized the research findings on CAFs in breast cancer.

Natural products remodel cancer-associated fibroblasts in desmoplastic tumors

Desmoplastic tumors have an abundance of stromal cells and the extracellular matrix which usually result in therapeutic resistance.Current treatment prescriptions for desmoplastic tumors are usually not sufficient to eliminate the malignancy.Recently,through modulating cancer-associated fibroblasts(CAFs)which are the most abundant cell type among all stromal cells,natural products have improved chemotherapies and the delivery of nanomedicines to the tumor cells,showing promising ability to improve treatment effects on desmoplastic tumors.In this review,we discussed the latest advances in inhibiting desmoplastic tumors by modeling CAFs using natural products,highlighting the potential therapeutic abilities of natural products in targeting CAFs for cancer treatment.